Together the Yankees and Red Sox have won 30 World Series in the last 100 years. The Yankees have won 9 times as many as the Red Sox. How many World Series have the Yankees won? Let the Yankees be represented by x and the Red Sox by y.

27World Series

21World Series

3 World Series

15World Series

Question

Together the Yankees and Red Sox have won 30 World Series in the last 100 years. The Yankees have won 9 times as many as the Red Sox. How many World Series have the Yankees won?  Let the Yankees be represented by x and the Red Sox by y.

		
27World Series

		
21World Series

		
3 World Series

		
15World Series

anonymous · Answer

hmm?

zzr0ck3r · Answer

Let $y$ be the amount of games the Yankees one.
Let $r$ be the amount of games the Red Sox one.

then they say the sum of these games is $30$
so

$x+y=30$

the Yankees won 9 times as many games

so if $x=1 y = 9$
    if $x = 2 y = 18$

in other words

$y=9x$

we plug $\uparrow$ this into the other equation for $y$

$x+y=30$  becomes $x+9x=30$

can you solve for $x$?

zzr0ck3r · Answer

change $r$ to $x$ is the second line